The degradation of arable land globally, largely due to declining soil organic matter (SOM), is a pressing issue. SOM is essential for various soil functions and significantly influences soil quality and health. Our study aimed to compare soil regenerative management methods for soil quality and basic essential functions and their effectiveness. We focused on selecting methods suitable for effectively monitoring changes during soil management. Over 3 years, we employed core methods, including minimum-till practices and natural mineral applications, to enhance soil physical characteristics, using cover crops and mulch to enrich SOM content. We assessed chemical soil properties such as total organic carbon (TOC), labile-C (permanganate oxidizable carbon [POXC], dissolved organic carbon [DOC], NaOH-soluble fulvic acids), glomalin content, and plant productivity. Our findings revealed that minimum-till had a significant time-dependent effect, increasing surface soil TOC by 17.58%, NaOH-soluble humic acids by 40.85%, and POXC by 77.75% over 3 years. Mulch and cover crop treatments enhanced specific carbon parameters and crop production. Different methods of assessing carbon levels proved useful for tracking time-dependent changes in soil quality. Labile-C forms such as DOC and POXC were most effective for shorter experiments, while TOC, glomalin, and NaF-soluble humic acids were better indicators for more extended experiments. These findings provide valuable insights for sustainable soil management practices.

The effect of low-dose, commercially available wastewater sludge compost (WSC; 15 t ha⁻¹) treatment was examined with or without arbuscular mycorrhizal fungal (AMF) inoculation on the nutritional status, heavy metal (HM) concentration and the rhizosphere activity of giant reed (Arundo donax L. var. BL clone (Blossom)) plants. Funneliformis mosseae (BEG12; AMF1), F. geosporum (BEG11; AMF2) or their combination (AMFmix) were applied as AMF treatments in a short-term pot experiment. The physiological and growth parameters of the host plants, the AMF root colonization and the microbiological enzyme activity of the mycorrhizosphere were examined. We assumed that the combined treatment (WSC + AMF) enhances the fertility of low-fertility acidic sandy soil. Neither the WSC treatment nor the AMF inoculations changed the extent of root colonization. Based on the results of root electrical capacitance and the phosphorous uptake, plant nutritional status was improved by WSC addition, without any negative impacts among the measured parameters. AMF treatments increased the enzyme activity in the soil and decreased the concentrations of the potentially toxic HMs (Cu, Mn, Pb, Zn) in roots, but that mitigation of Cu and Zn was compensated in shoots. According to the results of MicroResp™ measurements, the catabolic activity profile of the soil microbial community was changed in case of the AMF2 treatment. The efficient regulatory mechanism of giant reed might be able to adjust optimal/maximal colonization rate, and to select the preferential AMF partners, this supposed mechanism might be responsible for its invasiveness and tolerance to a wide range of environmental conditions.